Retractable cameras have been developed of the type comprising a camera housing having two sections, one of which carries the viewfinder lenses and is movable with relation to the other to an extended picture taking position and where the various lenses thereof are positioned to receive the external light rays, and to a retracted, non-picture taking position where the lenses are only in part shielded from dust and are in inoperative conditions. Exemplary of such a camera is the one disclosed in U.S. Pat. No. 3,864,705. U.S. Pat. No. 3,153,995 to Bretthauser et al. and is another example of such a retractable camera. These, exemplary retractable cameras were so designed that in the retracted conditions thereof at least some of the lens or other light passing surfaces thereof were exposed to dust. While some camera constructions incorporated a cover which enclosed all light passing portions thereof, these camera constructions were not of the type having retractable and extendable viewfinder carrying housing sections. Thus, in U.S. Pat. No. 3,495,223 to Bodlander, a cover is provided for the light passing surfaces, but the cover has to be removed from one end of the camera and inserted upon another portion thereof, which makes the cover inconvenient to use. Also, U.S. Pat. No. 3,153,375 discloses a non-retractable camera which utilizes a reciprocating film winding member which also acts as a cover on only one side of the camera housing for lens elements exposed only on that side.
Retractable cameras generally are kept in their retracted, compact condition when not in use and the act of moving the camera sections together into this condition is generally accomplished with much greater force and speed than the act of setting up the camera for use when the camera sections are separated. The act of moving the camera sections together effects a one frame length film advancement so the camera is automatically in condition for operation when the camera sections are subsequently separated. The type of camera disclosed in said U.S. Pat. No. 3,864,705 is one which utilizes a film cartridge where film metering to assure one frame advancement during each retraction of the movable section of the housing is achieved by a film metering pawl which is urged toward the film and adapted successively to enter one frame spaced film frame perforations in the film, where it operates means for disabling the film moving mechanism. The film moving mechanism generally includes a drive gear on the camera body which meshes with a gear on the film cartridge. The film metering pawl is subsequently withdrawn from a film perforation associated with the exposed frame of the film and moved in a direction opposite to that in which the film is being advanced, to permit another film metering operation to occur. The retraction of the movable camera section effects removal of the pawl from the film perforation so the pawl can engage an unapertured portion of the film and effect the termination of a film winding operation when the pawl enters a new perforation. Under normal conditions of operation, the film is advanced at a speed where the pawl can respond quickly enough to enter the next film perforation moved opposite the same. However, in those instances where the user, for some reason, exerts unusual force in pushing the movable section of the camera body to its retracted position, the film metering pawl may not move fast enough to enter the perforation moved opposite the same, with the result that the film overshoots its position where a film wind locking operation should take place. Depending upon the force exerted by the user, the extent of the overshoot can be as much as a frame and a half and causes overlapping of adjacent frames which spoils the pictures involved and wastes appreciable film. Apart from this shortcoming, retractable cameras of the type shown in U.S. Pat. No. 3,864,704 utilize complex gear train and clutch mechanisms to control film advancement which materially increase manufacturing costs.